Field of the Invention
The present disclosure relates to an organic light emitting diode display and a manufacturing method thereof, and, more particularly, to an organic light emitting diode display which includes an encapsulation layer including an inorganic layer containing carbon of 0.2 wt % to 6.2 wt % and an organic layer and a manufacturing method thereof.
Description of the Related Art
An organic light emitting diode display is a self-emission display device which has an organic light emitting diode which emits light to display an image. Since, unlike a liquid crystal display, the organic light emitting diode display does not require a separate light source, it is possible to reduce a thickness and a weight thereof relative to the thickness and weight required by a liquid crystal display. Further, since the organic light emitting diode display has high-grade characteristics such as low power consumption, high luminance, and a high response speed, the organic light emitting diode display receives attention as a next-generation display device for portable electronic apparatuses.
The organic light emitting diode is an element emitting and dissipating light generated when an electron and a hole are coupled with each other within the diode. Generally, the organic light emitting diode includes an electrode for injecting a hole (anode), an electrode for injecting an electron (cathode), and an emission layer and has a structure in which the emission layer is laminated between a positive electrode, which is the electrode for injecting a hole, and a negative electrode, which is the electrode for injecting an electron. In detail, when the electron is injected from the negative electrode of the organic light emitting diode and the hole is injected from the positive electrode, charges thus generated are moved in opposite directions relative to each other by the external electric field formed by the electrodes and then are coupled with each other in the emission layer to emit light, which is then dissipated from the emission layer. In the organic light emitting diode, the emission layer is made of a single molecular organic material or a polymer.
For example, the organic light emitting diode display (OLED) can be slim and flexible due to its more advantageous driving characteristics, and, as a result, much research relating to OLEDs is presently being conducted.
However, the organic light emitting diode display has the characteristic that the organic light emitting diode is deteriorated by the penetration of oxygen or moisture. Accordingly, in order to prevent oxygen or moisture from penetrating from the outside, an encapsulation structure for sealing and protecting the organic light emitting diode is required.
As the encapsulation structure, a thin film structure which covers the organic light emitting diode by a multilayer in which organic layers and inorganic layers are alternately laminated has been widely adopted. That is, the organic light emitting diode is sealed by alternately laminating the organic and inorganic layers on the organic light emitting diode of the substrate. Here, the organic layer mainly serves to give flexibility to the organic light emitting diode display, and the inorganic layer serves to prevent oxygen or moisture from penetrating.
As a method of forming an inorganic layer in the related art, sputtering, atomic layer deposition (ALD) or the like is used. However, since the formed inorganic layer is made of only an inorganic material, adhesion to the organic layer is weak, and detachment occurs along an interface between the inorganic layer and the organic layer. As a result, there is a problem in that the reliability of the OLED products is deteriorated.
In order to solve this problem, a plasma treatment is performed before and after forming the organic and inorganic layers, reducing the weakness of the adhesion between the organic layer and the inorganic layer. However, when the plasma treatment process is added, there is still a disadvantage in that the processing time is increased.
Accordingly, in order to form a more durable encapsulation layer against penetration of moisture and oxygen, a method of improving through a relatively simple process the adhesion between the organic layer and the inorganic layer while maintaining a barrier characteristic of the inorganic layer has been required.